weird sh(1) behaviour

[Richard A. O'Keefe]

In article <163 at cstw01.UUCP> meulenbr at cst.UUCP () writes:
>I noticed a peculiarity in sh which causes me a lot of trouble.
>The commands:
>	sh file
>and
>	sh <file
>are NOT equivalent.
>If you do think so, create a file which contains the command 
>	rm core

It isn't the shell's fault.  The sensitive command is 'rm'.
rm(1) will print an error message iff >>its<< standard input
is a terminal.  To verify this, in a directory having no 'core' file, do
	</dev/tty  rm core	# produces an error message
	</dev/null rm core	# is silent

If your script contains the line
	</dev/tty rm core
then both "sh script" and "sh <script" will produce the error message.

This is known and intended behaviour of the BSD /bin/rm; it doesn't
happen under V.3.  However, doing
	</dev/null rm file...
is harmless in V.3